hawkins



UNITE srarns rarnnr orricn.

ALFRED J. HAWKINS, orivionranAL, QUEBEC, CANADA.

raocnss or TREATING LEATHER.

No Drawing;

- To all whom it may concern:

Be it known that I, ALFRED J. HAWKINS,

a subject of the King of Great Britain, and resident of the city of Montreal, Province of Quebec, and Dominion of Canada, have invented certain new and useful Improvements in Processes of Treating Leather, of which the following is a full, clear, and exact description.

This invention relates to a process for the treatment of leather for the purpose of preserving it, increasing its flexibility, its durability, increasing its moisture-proof qualities and improving its appearance when finished.

According to my invention I first of all roughen the surface or wearing parts of the leather to be treated, so that the pores will be open to receive the impregnating fluid which I employ. This impregnating material consists of boiled linseed oil and in some cases boiled linseed oil mixed with neatsfoot or castor oil. The oil is heated to a temperature which may range from 100 F. to 150 F., but the temperature I prefer to employ 'is approximately 150 F. The leather is then subjected to a series of successive treatments in the manner which I will hereinafter explain.

It may be stated that my process does not contemplate the application of heat to the leather other than that which it receives from the impregnating oil, nor do I use pressure rollers nor any machinery for carrying out my process.

For the treatment of such material as sole leather for medium or heavy shoes, I find it preferable to use boiled linseed oil alone. The wearing surface is first roughened by passing a file or like instrument over the surface to expose the pores and the oil is then heated to a temperature of approximately 150 F. and applied in suiii-cient quantityto thinly cover the surface of the leather. This is allowed to stand for a period which may be from 6 to 2 hours but preferably for about 12 hours, whenthe oil will become partially dry or in a tacky or adhesive condition. The next step in my process is to repeat the application of oil, heated again to approximately the same temperature; Before this second application the temperature of the leather will have dropped and thefibers or membranes will Specification of Letters Patent. Patented Dec, 30, 1919, Applicationfiled November 12, 1918. Serial No. 262,192.

surface of-the leather and opens up the pores that a point of saturation of the wearingsurface has been reached.

This process should be carried out at a temperature of approximately 80 either in a closed heated room or in the open When the temperature is warm. The leather becomes heated upon the application of the oil but not to an excessive temperature, suliicient to burn it. The successive heating and cooling operations are essential to this process for the pores and membranes of the leather are first opened up to the oil and then allowed to cool and thicken. Repeated treatments result in a point of saturation of the leather that is not reached by any other process.

In the treatment of leather requiring greater flexibility such as that used in light shoes, I add to the boiled linseed oil approximately 1% of neatsfoot or castor oil. For harness leather I add approximately 3% of neatsfoot oil, and for belting I use approximately 5% of neatsfoot oil mixed with linseed or similar oil. The treatment is, however, exactly the same for all kinds of leather to which I apply my process.

In this treatment no heat is applied to the leather other than that contained in the heated oil and no pressure rollers are used to force the oil into the leather. 5 or 6 successive applications of hot oil are, however, sufiicient to thoroughly impregnate the pores and a quality of leather is produced which thin coating of boiled linseed oil heated to a temperature of approximately 150 F., allowing th oil to remain in contact with the leather for approximately 12 hours, then applying a second coating of oil and re peating the process until a series of coatings have been applied.

2. A process of treating leather which consists in successively applying a series of coatings of oil heated to a temperature from 100 F. to 150 F. and allowing each coating of oil to remain in contact with the leather for a period of at least 6 hours.

3. A process of treating leather which consists in applying to the leather a thin coating of boiled linseed oil mixed with less than neatsfoot heated to a temperature of approximately 150 F. and allowing the oil to remain in contact with the leather for a period of approximately 12 hours, and repeating this process until a series of applications of oil have been made to the leather.

4. A process of treating leather which consists in covering the leather with a thin coating of oil heated to a temperature of approximately 150 F., then allowing the oil to remain in contact with the leather for approximately 12 hours and until the temperature of the leather has cooled to approximately 80 F., then applying a second coating of oil heated to approximately 150 F. and again allowing the leather and oil to remain in contact and cool to a temperature of approximately 80 F. foranother 12 hour period, and repeating the alternative heating and cooling process until a series of coatings have been thus applied.

In witness whereof I hav hereunto set my hand.

ALFRED J. HAWKINS. 

